Research seeks to understand why some women have negative experiences with oral contraceptives, but others do not.

Many women around the world spend the better part of their reproductive years trying to avoid or delay pregnancy. And many of them at least try oral contraceptives (“the pill”) at some time. Yet there’s so much we don’t know about the pill’s effects on women. As a researcher, I have some ideas and am looking for more answers.

What’s the issue? The pill has been around for over 50 years?!

With 17% of women in the United States alone relying on oral contraceptives (Guttmacher Institute, 2013), we’d like to think that most of them are highly satisfied with this form of birth control. Especially since many women aren’t just using their pills for birth control–in addition to regulating fertility, 58% of U.S. women use oral contraceptives (OCs) as treatment for menstrual disorders and to regulate the timing and/or quantity of menstrual flow. Unfortunately, as many as 47% of new OC users stop the pill within the first 12 months of use (Sanders et al., 2001). Reasons cited for discontinuation include physical side effects (37% of cases), emotional side effects (33% of cases), problems with bleeding or spotting (18% of cases), and sexual side effects (8% of cases) (Sanders et al., 2001).

These high discontinuation rates have unwanted consequences for women. For a variety of reasons, discontinuation of a highly reliable method is often followed by a period in which no contraceptive method or a less-reliable method is used; approximately 20% of unplanned pregnancies in the U.S. each year are the result of OC discontinuation. In other words, the very women who are willing to try an OC soon find themselves at unexpected risk of unwanted pregnancy. These pregnancies pose serious threats to women’s health and well-being on multiple levels. Unplanned pregnancies place women, especially those who are young and/or underprivileged, at greater risk for maternal depression, lost education and career opportunities, and poor pre-natal care.

But haven’t OCs and their side effects been researched pretty extensively?

OCs have been researched extensively, but the major focus has been on lethal side effects. Fortunately, very few women experience lethal side effects today, thanks to improved pill formulation. I am in no way arguing that OCs are “dangerous” for most women. However, many women do experience negative side effects that disrupt their daily lives, and these side effects warrant our attention. Research on the pill , especially that conducted by pharmaceutical companies, tends to focus on a handful of “side effects” in isolation from other factors in women’s real lives. So far, results from such studies are inconsistent. Some authors report no differences between the experiences of women using and not using OCs, and conclude that OCs have been unfairly characterized. However, in many of these studies, women were questioned infrequently (often at monthly, three-month, or even six-month intervals) about the occurrence of side effects; such retrospective reporting is unable to track changes in experiences that may occur gradually or sporadically. Studies in which assessments occur more frequently show more OC-related changes. For example 9 out of 10 women on OCs reported significantly more negative feelings/experiences (such as headaches, nausea) than those taking placebos in a study that used frequent assessments. Of course, discontinuation studies (such as Sanders et al., 2001, mentioned above) also demonstrate that many women stop taking the pill due to side effects.

So what’s going on in the women who do have problems with oral contraceptives?

Well…we don’t know. Why women have such varied experiences with OCs is unknown and understudied, but here are a couple of hypotheses that have been suggested:

Some researchers have hypothesized that bad experiences with OCs result from negative expectations about the pill. According to this argument, side effects are considered little more than “noise” that is created and exaggerated by women and their health care providers. Although it is true that some women do have negative expectations of OCs, a causal link between expectations and experiences has never been established.

Other researchers have hypothesized that biological (especially hormonal) variation between individuals accounts for differential OC experiences. This seems plausible, as hormonal and pharmacokinetic variation within and between populations has been documented.

So I am testing these two hypotheses for my dissertation research. I care about this project because understanding the reasons why some women have intolerably negative experiences with OCs will lead to improved health care for women who desire effective, reversible contraception. Ideally, results from this project can improve OC prescribing practices; if women with certain body types, hormone levels, or tendencies for other bodily or psychological experiences (headaches, nausea, anxiety, etc.) respond negatively to particular types of OCs, prescribers could avoid this kind of miss-match. If women with negative fears or expectations have worse experiences with OCs, then improved counseling to women could be offered. These changes in prescribing practices could have long-term consequences for improving women’s lives by enabling them to plan their pregnancies and secure stable futures.